This invention relates generally to novel genes encoding proteins that have use as anti-cancer therapeutics.
Related Art
One of the hallmarks of cells that have become cancerous is the change in the gene expression pattern in those cells as compared to normal, non-cancerous cells. An intricate series of cell signaling events leads to this so called xe2x80x9cdifferential gene expressionxe2x80x9d, resulting in conversion of a normal cell to a cancer cell (also known as xe2x80x9concogenesisxe2x80x9d or xe2x80x9ccell transformationxe2x80x9d). A number of cell signaling pathways have been implicated in the process of cell transformation, such as, for example, the cadherin pathway, the delta/jagged pathway, the hedgehog/sonic hedgehog pathway, and the wnt/wingless pathway (Hunter, Cell, 88:333-346 [1997]; Currie, J. Mol. Med., 76:421-433 [1998]; Peifer, Science, 275:1752-1753 [1997]. Interestingly, these same pathways are involved in cell morphogenesis, or cell differentiation, during embryo development (Hunter, supra; Cadigan et al., Genes and Develop., 11:3286-3305 [1997]).
The wnt genes encode glycoproteins that are secreted from the cell. These glycoproteins are found in both vertebrate and invertebrate organisms. Currently, there are at least 20 wnt family members, and these members are believed to function variously in control of growth and in tissue differention. Recently, discovery of a novel gene was identified in Xenopus and mouse and has been termed dickkopf-1 (xe2x80x9cdkk-1xe2x80x9d). This gene is purportedly a potent antagonist of wnt-8 signaling (Glinka et al., Nature, 391:357-362 [1998]). Interestingly, this gene is also purportedly involved in morphogenesis in the developing embryo (Glinka et al., supra). This gene thus represents a novel growth factor which may be useful in tissue regeneration, and also represents a means for potentially inhibiting cell transformation via wnt signaling.
The Frzb proteins and the protein Cerberus are examples of secreted proteins that purportedly inhibit wnt signaling (Brown, Curr. Opinion Cell Biol., 10:182-187 [1998).
PCT WO 98/35043, published Aug. 13, 1998, describes human SDF-5 proteins which are purportedly useful in regulating the binding of wnt polypeptides to their receptors.
PCT WO 98/23730, published Jun. 4, 1998, describes transfecting tumors cells with wnt-5a to purportedly decrease tumorigenicity. Wnt-5a purportedly is an antagonist of other wnts.
In view of the devastating effects of cancer, there is a need in the art to identify additional genes that may serve as antagonists of proteins involved in cell transformation.
Accordingly, it is an object of this invention to provide nucleic acid molecules and polypeptides that may be useful as anti-cancer compounds.
It is a further object to provide methods of altering the level of expression and/or activity of such polypeptides in the human body.
Other related objects will readily be apparent from a reading of this disclosure.
In one embodiment, the present invention provides an isolated nucleic acid molecule encoding a biologically active DKR polypeptide selected from the group consisting of:
(a) the nucleic acid molecule comprising SEQ ID NO:1;
(b) the nucleic acid molecule comprising SEQ ID NO:2;
(c) the nucleic acid molecule comprising SEQ ID NO:3;
(d) the nucleic acid molecule comprising SEQ ID NO:4;
(e) the nucleic acid molecule comprising SEQ ID NO:5;
(f) the nucleic acid molecule comprising SEQ ID NO:6;
(g) the nucleic acid molecule comprising SEQ ID NO:7;
(h) the nucleic acid molecule comprising SEQ ID NO:75;
(i) the nucleic acid molecule comprising SEQ ID NO:76;
(j) the nucleic acid molecule comprising SEQ ID NO:77;
(k) the nucleic acid molecule comprising SEQ ID NO:78;
(l) the nucleic acid molecule encoding the polypeptide of SEQ ID NO:8;
(m) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:9;
(n) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:10, or a biologically active fragment thereof;
(o) a nucleic acid molecule encoding the polypeptide of SEQ ID No:11, or a biologically active fragment thereof;
(p) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:12, or a biologically active fragment thereof;
(q) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:13, or a biologically active fragment thereof;
(r) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:14, or a biologically active fragment thereof;
(s) a nucleic acid molecule that encodes a polypeptide that is at least 85 percent identical to the polypeptide of SEQ ID NOs:10, 11, 12, 13, or 14;
(t) a nucleic acid molecule that encodes a biologically active DKR polypeptide that has 1-100 amino acid substitutions and/or deletions as compared with the polypeptide of any of SEQ ID NOs:8, 9, 10, 11, 12, 13, or 14; and
(u) a nucleic acid molecule that hybridizes under conditions of high stringency to any of (c), (d), (e), (f), (g), (h), (i), (k), (l), (m), (n), (o), (p), (q), (r), (s), and (t) above.
In another embodiment, the invention provides an isolated nucleic acid molecule that is the complement of any of the nucleic acid molecules above.
In yet another embodiment, the invention provides an isolated nucleic acid molecule encoding a biologically active DKR polypeptide selected from the group of: amino acids 16-350, 21-350, 22-350, 23-350, 33-350, or 42-350, 21-145, 40-145, 40-150, 45-145, 45-145, 145-290, 150-290, 300-350, or 310-350 of SEQ ID NO:9; amino acids 15-266, 24-266, or 32-266 of SEQ ID NO:10; amino acids 17-259, 26-259, or 34-359 of SEQ ID NO:12; and amino acids 19-224, 20-224, 21-224, or 22-224 of SEQ ID NO:14.
In other embodiments, the invention provides vectors comprising the nucleic acid molecules, and host cells comprising the vectors.
In still another embodiment, the invention provides a process for producing a biologically active DKR polypeptide comprising the steps of:
(a) expressing a polypeptide encoded by any of the nucleic acid molecules herein in a suitable host; and
(b) isolating the polypeptide.
In still one other embodiment, the invention provides a biologically active DKR polypeptide selected from the group consisting of:
(a) the polypeptide of SEQ ID NO:8;
(b) the polypeptide of SEQ ID NO:9;
(c) the polypeptide of SEQ ID NO:10;
(d) the polypeptide of SEQ ID NO:11;
(e) the polypeptide of SEQ ID NO:12;
(f) the polypeptide of SEQ ID NO:13;
(g) the polypeptide of SEQ ID NO:14;
(h) a polypeptide that has 1-100 amino acid substitutions or deletions as compared with the polypeptide of any of (a)-(g) above; and
(i) a polypeptide that is at least 35 percent identical to any of the polypeptides of (c)-(h) above.
In still one other embodiment, the invention provides the following polypeptides: a polypeptide that is amino acids 16-350, 21-350, 22-350, 23-350, 33-350, or 42-350, 21-145, 40-145, 40-150, 45-145, 45-145, 145-290, 145-300, 145-350, 150-290, 300-350, or 310-350 of FIG. 9, a polypeptide that is amino acids 15, 266, 24-266, or 32-266 of FIG. 10, a polypeptide that is amino acids 17-259, 26-259, or 34-259 of FIG. 12, and a polypeptide that is amino acids 19-224, 20-224, 21-224, or 22-224 of FIG. 14.